Card type semiconductor device

Abstract

A card type semiconductor device includes a main circuit board and a first sub-circuit-board equipped with a main memory. The main circuit board is connected to the first sub-circuit-board through an FPC. A first TCP equipped with the CPU and a second TCP equipped with the I/O sub-system chip are mounted on the top and bottom surfaces of the main circuit board. The first and second TCPs are mounted to directly oppose each other. The card type semiconductor device is used as a card type computer. The main circuit board and the sub-circuit-board face each other by bending the FPC and enclosing the main circuit board and the sub-circuit-board in a card-shaped thin housing. The card type semiconductor device achieves a high density packaging in a small form factor. The card type semiconductor device supports high speed operations and provides a structure for adaptation to new applications quickly and inexpensively by allowing easy replacement of the sub-circuit-board with other sub-circuit boards that perform a wide range of functions.

What is claimed is: 
     
       1. A card type semiconductor device, comprising: a main circuit board having a first side and a second side, electronic components being mounted on the main circuit board on both the first and second sides, the electronic components on the first side of the main circuit board opposing the electronic components on the second side of the main circuit board;   a sub-circuit-board coupled to the main circuit board mounted with electronic components wherein the main circuit board and the sub-circuit-board are detachably electrically coupled through a pair of electrical connectors so that the main circuit board faces the sub-circuit-board; and   a card-shaped thin housing for enclosing the main circuit board and the sub-circuit board, wherein the electronic components on the first side of the main circuit board are thermally connected to the electronic components on the second side of the main circuit board through thermal via-holes bored through the main circuit board so that heat is transferred between the electronic components.   
     
     
       2. The card type semiconductor device of claim 1, wherein the main circuit board and the sub-circuit-board are fixed together into one unit by a spacer device so that the main circuit faces the sub-circuit-board. 
     
     
       3. The card type semiconductor device of claim 1, wherein at least a surface of the card-shaped thin housing is made of a metal plate protruding outwardly. 
     
     
       4. The card type semiconductor device of claim 1, further comprising a connector having a large number of terminals for connecting to an external apparatus. 
     
     
       5. The card type semiconductor device of claim 4, wherein two of the terminals are a dot clock signal terminal connected to an external liquid crystal display and a grounding terminal adjacent to the dot clock signal terminal. 
     
     
       6. The card type semiconductor device of claim 4, wherein the large number of terminals are arranged into a plurality of rows, three terminals of one of the plurality of rows being an R-signal terminal, a G-signal terminal and a B-signal terminal and three terminals of an adjacent row of the plurality of rows being an R-return-signal terminal, a G-return-signal terminal and a B-return-signal terminal corresponding to the R-signal terminal, the G-signal terminal and the B-terminal, respectively, the R-return-signal terminal, the G-return-signal terminal and the B-return-signal terminal facing the R-signal terminal, the G-signal terminal and the B-signal terminal, respectively, and all six terminals being connected to an external CRT. 
     
     
       7. The card type semiconductor device of claim 4, wherein the large number of terminals are arranged into a plurality of rows, and the plurality of rows are divided into horizontally asymmetric portions by a plurality of ribs. 
     
     
       8. The card type semiconductor device of claim 7, wherein the plurality of ribs prevent the connector from being erroneously connected to a mating connector. 
     
     
       9. The card type semiconductor device of claim 1, further comprising a second sub-circuit-board mounted on one of the first and second surfaces of the main circuit board, wherein an analog circuit is mounted on the second sub-circuit-board and a power supply terminal of the second sub-circuit-board is connected to a power supply line of the main circuit board. 
     
     
       10. The card type semiconductor device of claim 1, further comprising: a plurality of other sub-circuit-boards, a plurality of other electronic components mounted on the plurality of other sub-circuit-boards, wherein at least a first and second ones of the plurality of other sub-circuit-boards are mounted on the first and second sides of the main circuit board, respectively, the first and second ones of the plurality of other sub-circuit-boards being mounted opposing each other so that mounting positions of the first and second ones of the plurality of other sub-circuit-boards are symmetric with respect to the main circuit board,   wherein the card-shaped thin housing also encloses the plurality of other sub-circuit-boards.   
     
     
       11. The card type semiconductor device of claim 1, further comprising: a first IC package mounted on a first surface of the main circuit board and a second IC package mounted on a second surface of the main circuit board;   a first plurality of connection portions for connecting a plurality of leads of the first IC package with a first plurality of lands formed on the first surface of the main circuit board; and   a second plurality of connection portions for connecting a plurality of leads of the second IC package with a second plurality of lands formed on the second surface of the main circuit board, wherein the first IC package opposes the second IC package and the first plurality of connection portions on the first surface of the main circuit board opposes the second plurality of connection portions on the second surface of the main circuit board.   
     
     
       12. The card type semiconductor device of claim 11, wherein a portion of the second plurality of connection portions corresponding to a side of the second IC package opposes a portion of the first plurality of connection portions corresponding to a side of the first IC package. 
     
     
       13. The card type semiconductor device of claim 11, wherein the second plurality of connection portions corresponding to all four sides of the second IC package opposes the first plurality of connection portions corresponding to all four sides of the first IC package. 
     
     
       14. The card type semiconductor device of claim 11, wherein the first and second IC packages have electronic components that operate in conjunction with one another. 
     
     
       15. The card type semiconductor device of claim 14, wherein the first IC package contains a CPU and the second IC package contains an I/O system which operates with the CPU. 
     
     
       16. The card type semiconductor device of claim 11, wherein at lease one of the first IC package and the second IC package is a tape carrier package. 
     
     
       17. A card type semiconductor device, comprising: a first IC package;   a second IC package, the first IC package and the second IC package being mounted on a first surface and a second surface of a printed circuit board, respectively, so that the first and second IC packages oppose each other, the first and second IC packages being connected to the first and second surfaces of the printed circuit board, respectively, through a die bonding, wherein the first IC package and the second IC package are thermally connected to each other through thermal via-holes bored through the printed circuit board so that heat is transferred between the first and the second IC packages;   an other circuit board coupled to the printed circuit board; and   a card-shaped thin housing for enclosing the printing circuit board and the other circuit board.   
     
     
       18. The card type semiconductor device of claim 17, wherein leads of the first and second IC packages are coated with a thermally conductive resin. 
     
     
       19. The card type semiconductor device of claim 1, wherein a CPU is mounted on the sub-circuit-board. 
     
     
       20. The card type semiconductor device of claim 19, wherein the CPU and the electronic components mounted on the sub-circuit-board are coupled to only a bottom surface of the sub-circuit-board facing the main circuit board. 
     
     
       21. The card type semiconductor device of claim 1, wherein the pair of connectors includes a female connector and a male connector. 
     
     
       22. A card type semiconductor device, comprising: a main circuit board having a first side and a second side, electronic components being mounted on the main circuit board on both the first and second sides, the electronic components on the first side of the main circuit board opposing the electronic components on the second side of the main circuit board;   a sub-circuit-board coupled to the main circuit board mounted with electronic components;   a notch portion formed in a side edge portion of the main circuit board;   a flexible printed circuit connected to the main circuit board and the sub-circuit-board through the notch portion to minimize curvature of the flexible printed circuit and minimize stress on the main circuit board and the sub-circuit-board; and   a card-shaped thin housing for enclosing the main circuit board and the sub-circuit board.   
     
     
       23. The card type semiconductor device of claim 22, wherein a CPU is mounted on the main circuit board. 
     
     
       24. The card type semiconductor device of claim 22, wherein the flexible printed circuit is connected to one of the first and second surfaces of the main circuit board and the sub-circuit-board faces the main circuit board by bending the flexible printed circuit. 
     
     
       25. The card type semiconductor device of claim 22, wherein the main circuit board and the sub-circuit-board are fixed together into one unit by a spacer device so that the main circuit faces the sub-circuit-board. 
     
     
       26. The card type semiconductor device of claim 22, wherein at least a surface of the card-shaped thin housing is made of a metal plate protruding outwardly. 
     
     
       27. The card type semiconductor device of claim 22, further comprising a connector having a large number of terminals for connecting to an external apparatus. 
     
     
       28. The card type semiconductor device of claim 27, wherein the large number of terminals are arranged into a plurality of rows, and the plurality of rows are divided into horizontally asymmetric portions by a plurality of ribs, three terminals of one of the plurality of rows being an R-signal terminal, a G-signal terminal and a B-signal terminal and three terminals of an adjacent row of the plurality of rows being an R-return-signal terminal, a G-return-signal terminal and a B-return-signal terminal corresponding to the R-signal terminal, the G-signal terminal and the B-terminal, respectively, the R-return-signal terminal, the G-return-signal terminal and the B-return-signal terminal facing the R-signal terminal, the G-signal terminal and the B-signal terminal, respectively, and all six terminals being connected to an external CRT. 
     
     
       29. The card type semiconductor device of claim 28, wherein the plurality of ribs prevent the connector from being erroneously connected to a mating connector. 
     
     
       30. The card type semiconductor device of claim 22, further comprising a second sub-circuit-board mounted on one of the first and second surfaces of the main circuit board, wherein an analog circuit is mounted on the second sub-circuit-board and a power supply terminal of the second sub-circuit-board is connected to a power supply line of the main circuit board. 
     
     
       31. The card type semiconductor device of claim 22, further comprising: a first IC package mounted on a first surface of the main circuit board and a second IC package mounted on a second surface of the main circuit board;   a first plurality of connection portions for connecting a plurality of leads of the first IC package with a first plurality of lands formed on the first surface of the main circuit board; and   a second plurality of connection portions for connecting a plurality of leads of the second IC package with a second plurality of lands formed on the second surface of the main circuit board, wherein the first IC package opposes the second IC package and the first plurality of connection portions on the first surface of the main circuit board opposes the second plurality of connection portions on the second surface of the main circuit board.   
     
     
       32. The card type semiconductor device of claim 31, wherein a portion of the second plurality of connection portions corresponding to a side of the second IC package opposes a portion of the first plurality of connection portions corresponding to a side of the first IC package. 
     
     
       33. The card type semiconductor device of claim 31, wherein the second plurality of connection portions corresponding to all four sides of the second IC package opposes the first plurality of connection portions corresponding to all four sides of the first IC package. 
     
     
       34. The card type semiconductor device of claim 31, wherein the first and second IC packages have electronic components that operate in conjunction with one another. 
     
     
       35. The card type semiconductor device of claim 34, wherein the first IC package contains a CPU and the second IC package contains an I/O system which operates with the CPU. 
     
     
       36. The card type semiconductor device of claim 31, wherein at lease one of the first IC package and the second IC package is a tape carrier package. 
     
     
       37. The card type semiconductor device of claim 22, further comprising a CPU mounted on the main circuit board adjacent to the card-shaped thin housing. 
     
     
       38. The card type semiconductor device of claim 22, further comprising: a plurality of other sub-circuit-boards having a plurality of other electronic components mounted on the plurality of other sub-circuit-boards, wherein at least a first and second ones of the plurality of other sub-circuit-boards are mounted on the first and second sides of the main circuit board, respectively, the first and second ones of the plurality of other sub-circuit-boards being mounted opposing each other so that mounting positions of the first and second ones of the plurality of other sub-circuit-boards are symmetric with respect to the main circuit board the card-shaped thin housing also enclosing the plurality of sub-circuit-boards.